When a scroll type fluid compressor is used, for example, as a compressor for an automotive air conditioning system, there is a need to produce relative high fluid pressures. However, the pressure tends to cause the pressurized fluid to leak from any clearance which may exist between the axial end surface of the scroll element of one scroll and the surface of the end plate of the other scroll. The leakage of the compressed fluid decreases the efficiency of the compressor.
It is known to try to minimize the axial clearance between scrolls by inserting a shim or shims in the assembly of a scroll type fluid compressor. However, it is difficult to get the correct combination of shims, exactly corresponding to the axial clearance between the scrolls of a particular compressor. Experimentation to find the right combination of shims also limits production speed in assembling a scroll compressor.
It is also known to adjust the axial clearance between scrolls by means of an adjusting screw fixed to the fixed scroll. However, in this type of structure, deflection of the fixed scroll may be caused by the particular location of the adjusting screw position. Also, this structure cannot correct alignment problems between the scrolls.